As a result, such ordinances that a federal judge had overturned won't go into effect.

In 2014, Maui County voters approved a ban on genetically engineered farming. Kauai County had imposed notification requirements for pesticide use by large companies, while Hawaii County had prohibited open-air testing of genetically modified crops.

Callahan ruled that the state’s pesticide law is comprehensive, and that the Legislature meant for it to be “exclusive of additional, local rules”.

The decision was a victory for seed companies that perform research in Hawaii such as Monsanto and Syngenta.

Dan Clegg, head of business operations for Monsanto Hawaii, told Honoluu Civil Beat that the company will continue “to support the communities in Maui, Molokai and Oahu where our approximately 1,000 local employees live and work”.

Syngenta spokeswoman Laurie Yoshida said the company is happy with the ruling, adding that it continues to voluntarily report its pesticide use on Kauai through the Good Neighbor Program.

George Kimbrell, senior attorney for the Center for Food Safety, which pushed for the bans, told The Associated Press that his group is “considering all legal options, including appeal”.